1

Retinal vascular diseases 2

Dr. Mohammad Shehadeh

2

Retinal vein occlusion

Classification: Branch retinal vein occlusion

Central retinal vein occlusion

3

Pathogenesis

Atherosclerosis of the retinal arterioles make them rigid and they compress the veins when they cross it causing it to thrombose causing branch retinal vein occlusion

Central retinal vein and artery share a common adventitial sheath posterior to lamina cribrosa, so that atherosclerosis changes of the artery may compress the vein causing its thrombosis and cause central retinal vein occlusion

4

Risk factors of retinal vein occlusion Old age : 50% over the age of 65 Systemic conditions: Hypertention,

hyperlipidemia, diabetes, smoking and obesity. Raised intraocular pressure Inflammatory diseases such as sarcoidosis Thrombophilic disorders : inherited or aquired

5

Branch retinal vein occlusion

Presentation: depend on the extent of macular involvement.

1. If the macula not involved it may be asymptomatic

2. Sudden onset of blurred vision3. Metamorphopsia4. Relative visual field defect

6

signs

Visual acuity: depend on the extent of macular involvement

Fundus signs:1. Venous dilatation and tortuousity2. Flame shaped hemorrhages3. Retinal edema4. Cotton wool spots

7

8

FA : eary hypofluorescence due to blockage by edema and blood and late hyperfluorescence due to leakage of dye

Prognosis: reasonably good 50% return to visual acuity of 6/12 or

better within 6 mounths Vision threatenin complications of BRVO:1- chronic macular edema2- neovascularization: NVD or NVE

9

Management of BRVO We review the patient every 6-12 weeks When the hemorrhages resolve we do FA:1. FA shows good macular perfusion and vision is good

no treatment is required2. FA shows macular edema with good macular perfusion

and vision is 6/12 or worse after 3 months laser photocoagulation should be considered but if vision is better than 6/12 no treatment is needed

3. FA shows macular non perfusion and visual acuity is poor laser treatment will not improve vision.

4. FA shows 5 or more disc diameters of non perfusion the patient should be reviewed every 4 months for 1-2 years because there is risk of neovascularization

10

11

Central retinal vein occlusion

Non-ischemic CRVO : 75% of cases

Ischemic CRVO

12

Non-ischemic CRVO

Clinical features: Presentation: with sudden blurred vision Visual impairment : moderate to severe Afferent pupillary defect (APD): abscent or

mild

13

Fundus features:

1. Tortuousity and dilatation of all branches of central retinal vein

2. Retinal dot-blot and flame shaped hemorrhages all over the four retinal quadrant

3. Occasional cotton wool spots

4. Mild to moderate optic disc edema and macular edema

14

15

FA : shows

1. Delayed venous return

2. Good retinal capillary perfusion

3. Late leakage

Course:

Most signs resolve over 6-12 months

Conversion to ischemic type can occur in 34% within 3 years

16

Prognosis:

In cases that do not convert to ischemic type, prognosis is good, with return of visual acuity to normal or near normal in about 50%

Management: Follow up should be for years to detect

conversion to ischemic CRVO High intensity laser to create anastomosis

between retinal vein and choroidal vein, but it may cause fibrosis at the laser site or hemorrhage from ruptured vein

17

Ischemic central retinal vein occlusionClinical features: Presentation: sudden and severe visual

impairment Visual impairent: severe APD : severe

18

Fundus features:

1. Marked tortuousity and engorgement of all branches of central retinal vein

2. Extensive dot-blot and flame shaped hemorrhages

3. Cotton wool spots which may be numerous

4. Macular edema

5. Severe optic disc edema

19

20

FA: central masking by retinal hemorrhages and extensive areas of capillary non-perfusion

Course: most acute signs resolve over the next 9-12 months

Prognosis: extremely poor due to macular ischemia, rubeosis iridis develop in about 50% of cases usually 2-4 months and there is high risk of neovascular glaucoma

21

Management: Follow up monthly for 6 months in order to

detect rubeosis iridis and with gonioscopy to detect angle neovascularization

If neovascularization develops , laser PRP should be done without delay

22

Retinal artery occlusion

Branch retinal artery occlusion (BRAO)

Central retinal artery occlusion (CRAO)

Cilioretinal artery occlusion

23

Causes:1. Atherosclerosis-related thrombosis(most

common cause of CRAO) 80% of cases2. Carotid embolism3. Giant cell arteritis4. Cardiac embolism5. Priarteritis in cases of systemic

vasculitis, such as SLE , Behcet…Etc.6. Thrombophilic disorders such as

antiphospholipid syndrome

24

Branch retinal artery occlusion BRAO is most frequently caused by embolism Presentation: with sudden and profound

sectoral visual field loss Fundus features:

1. retinal cloudining corresponding to the area of occluded artery

2. narrowing and segmentation of blood column

3. One or more emboli may be present

25

26

FA:

1. Delay in arterial filling

2. Masking of background fluorescence by retinal swelling which is confined to the involved sector

Prognosis :

Poor unless the obstruction can be relieved within few hours

27

Central retinal artery occlusion

CRAO is most frequently the result of atherosclerosis

Presentation: sudden and profound loss of vision except when a portion of the papillomacular bundle is supplied by cilioretinal artery, when central vision is preserved

APD is profound or total

28

Fundus features:

1. Attenuation of arteries and veins with segmentation of the blood column

2. Extensive retinal cloudiness

3. Cherry red spot : which is an red-orange reflex from intact choroid appearing through the thin fovea

4. In eyes with cilioretinal artery , part of the macula will appear normal in colour

29

30

FA:1. Shows delay in arterial filling 2. Masking of background choroidal

fluorescence by retinal swelling3. A patent cilioretinal artery will fill during

the early phase Prognosis:Is poor due to retinal infarction Rubeosis iridis may occur and need PRP

laser

31

Cilioretinal artery occlusion

Cilioretinal artery present in 20% of population

It arises from posterior ciliary circulation but supplies the retina, in the area of the macula and papillomacular bundle

32

Classification:

1. Isolated: typically affects young patients with an associated systemic vasculitis

2. Combined with CRVO: has similar prognosis to non-ischemic CRVO

3. Combined with anterior ischemic optic neuropathy: affects patients with giant cell arteritis and carry a very poor prognosis

33

34

Presentation: with acute, severe loss of central vision

Fundus: cloudiness localized to that part of the retina normally perfused by the vessel

FA: shows corresponding filling defect

35

Treatment of acute retinal artery occlusion Initial treatment:1. Ocular massage: by 3 mirror contact lens,

press for 10 seconds then release for 5 seconds.

2. Sublingual isosorbide dinitrite: to dilate perepheral blood vessles and decrease resistance

3. Lowering of IOP with intravenous acetazolamide and mannitol

36

Subsequent treatment

If the above mentioned measures are unsuccessful after 20 minutes we can do the following:

1. Anterior chamber paracentesis

2. IV streptokinase ( thrombolytic drug )

3. Retrobulbar injection of tolazoline to decrease retrobulbar resistance to flow

37

Hypertensive retinopathy

Hypertension is diagnosed on blood pressure reading on several consecutive occasions 140/90 or over.

38

Retinal changes:

1. Arterial narrowing :

May be focal or generalized

Severe hypertention may lead to obstruction of precapillary arterioles and the development of cotton wool spots

2. Vascular leakage:

Leading to flame shaped retinal hemorrhages , retinal edema , hard exudates and macular star.

Swelling of the optic disc is the hallmark of malignant hypertension.

39

3. Arteriosclerrosis:

Involves thickenning of the vessel wall

The most important sign is arteriovenous nipping

Grades of arteriosclerosis:

Grade 1 : subtle broadening of arteriolar light reflex

Grade 2 : bending of veins at arteriovenous crossings

Grade 3 : copper wiring

Grade 4 : silver wiring

40

41

Choroidal changes:

Rare and developes in acute hypertensive crisis

1. Elshing spots: focal choroidal infarcts

2. Siegrist streaks: fibrinoid necrosis

3. Exudative retinal detachment: associated with toxemia of pregnancy.

42

43

Retinopathy of prematurity (ROP) It is aproliferative retinopathy affecting pre-

term infants of low birth weight who have been exposed to high ambient oxygen concentration

The vessles reach the nasal periphery after 8th month of gestation but do not reach the temporal perephery until 1 month after delivery

The incompletely vascularized temporal retina is particularly susceptible to oxygen damage especially in preterm infants

44

Active ROP Severity: determined in terms of (a)location (b)extent (c)

stages (d) plus disease

(a) Location : It is determined by three zones centered on the optic disc

45

(b) Extent: determined by the number of clock hours of the retina involved

(c) Staging :

Stage1: demarcation line

Stage 2: ridge

Stage 3: ridge with extraretinal fibrovascular proliferation

Stage 4: subtotal retinal detachment

Stage 5: total retinal detachment

46

47

Oher considerations Plus disease: signifies

tendency to progression. Characterized by:

1- failure of pupil to dilate

2- development of vitreous haze

3- dilatated tortuous vessles

4- Preretinal and vitreous hemorrhage

48

Threshold disease It is the indication of treatment in ROP.

It is the presence of five consequetive hours or 8 non-consequetive hours of stage 3 in zone 1 or 2 associated with plus disease

49

screening

Babies born at or before 31 weeks or weighing 1500g or less should be screened for ROP

When to screen?

At the gestational age 34 or 4 weeks post delivery which ever comes later.

50

Treatment:

Ablation of immature retina by cryotherapy or laser ( successful in 85% of cases only)

Retinal surgery in cases of retinal detachment

51

52